Heat treating powdered material



Sept. 13, 1938. c; L. RILEY HEAT TREATING POWERED MATERIAL Filed Jan.19, 1957 n m z a a 4 A fw a a i Y f u z B .W *5" l i 3 +2 INVENTOR.

1 ATTORNEYS U Patented Sept. 13, 1938 UNITED STATES PATENT OFFICE 3Claims. (01. 34-34) This invention relates to heat treatment of or otherorganic material.

In roasting cofiee as the art is practiced today, I

it is necessary to roast the outside of the coifee bean too much inorder to heat the inner part of the bean sufllciently. The coifee is,therefore, not uniformly roasted.

An object of this invention is a method of roasting coffee in whichgreen coffee in powdered form is subjected to accurately controlledtemperature, whereby all the coffee is subjected to the same temperatureand uniform roasting thereof is eilected.

The apparatus for treating coffee according to the present inventioncomprises a cylindrical chamber having insulated walls, top and bottom,with a centrifugal atomizerinserted through the ceiling of the chamber.A series of gas jets with reflectors focused at or near the atomizer ispro vided near the ceiling of the roasting chamber..

The powdered green coifee is subjected to an atomizer which dischargesthe powdered coffee in a horizontal plane from which the coffee fallsmaterial, the products of combustion and'also the fumes, if any, fromthe roasted material.

Other objects; novel features and advantages of this invention willbecome apparent from the following specification and accompanying draw-I5 which consists essentially of a conical housinging, wherein: v

Fig. 1 is a vertical section through an apparatus for practicingtheinvention;

Fig. 2 is a section on the line 22 of Fig. l,

f/ and Fig. 3 is a sectionon the line 3-4 of Fig. 1. Aicylindrical towerIII terminates at its bottom in a hopper ll, Near the top of the toweris arranged a series of nozzles l2 which are con- 0 nected to a pipe l3through which properly carbureted gas is supplied at uniform pressure,These nozzles l2 are arranged radially of the tower and are uniformlyspaced. In the ceiling M of the tower is provided a centrifugal sprayeri6 through which extends a spindle I! having a disk ii at its lower end.At the upper end of the spindle I l is provided a pulley I9 towhichpower is transmitted by any suitable means for effecting rotation of thespindle.

A hopper 20 has its outlet communicating with a blower 2|, the outlet ofwhich leads to the interior of the housing It through a pipe 22.Reflectors 23 are provided on the nozzles l2 and are focused on or nearthe disk ill for reflecting to the sprayer heat generated bythe'combustio of gas supplied through the nozzles.

Near the bottom of the'tower is provided a conical shield 24, the upperend of which is in contact with the inner periphery of the tower and thelower end of which extendsa short distance into the top of a cylinder 25supported by the hopper ll, there being slight clearance between thecone 24 and cylinder 25. These two members form an annular duct with thebottom portion'of the tower l0 and the upper portion of the hopper IIand an exhaust fan 26 has its inlet connected with such duct. Theclearance between the cone 24 and cylinder 25 provides a passageway forthe ingress of gas and vapor into the duct. 1

In the practice of; the invention, powdered green coffee or othersimilar material to be heat treated is charged into the hopper 20 from asuitable supply source. The blower 2| supplies a stream of the powderedmaterial to the disk 18 which is rotated at a high speed. The diskdischarges the powdered material in a horizontal plane from which itfalls to the bottom of the tower. The powdered material is subjected tothe temperature produced'by the heat developed by combustion of gassupplied through the nozzles l2 and the quantity of the powderedmaterial sprayed by the disk i8 is so proportioned to the heat suppliedthat it is roasted to the de-v sired extent.

Theroasting temperature is accurately controlled by regulation. of thesupply of gas and the powdered material is heated particle by particleunder uniform conditions so that uniform roasting of the material iseffected. Moisture evaporated from the powdered material, products ofcombustion and also the fumes, if any, from the roasted material, areremovedbythe exhauster 28 through the duct previously de- 'ceptacle 21.

Although the method has been specifically disl6 closed in connectionwith roasting coflee, it is to be understood that it is equallyapplicable to the drying or roasting or other similar organic materials.Furthermore, the method may be used also for drying to remove water fromsolutions or suspensions of solid material. V

In such event, the solution or suspension of solid material in liquidwould be supplied to the hopper 20 and fed through the pipe 22 to thesprayer l8. As previously described, the sprayer l8 projects the liquidinto a horizontal plane and withdrawing gases and vapors from saidchamber below the spray level.

2. The process of roasting cofiee which comprises centrifugally sprayingsaid coflee in powdered form into a horizontal plane near the top of achamber, eiIecting combustion of a plurality of gas jets uniiormlyspaced around said chamber adjacent said plane, reflecting heat fromsaid jets into said plane and withdrawing gases and vapors from saidchamber below the spray level.

3. Apparatus for heat treating powdered material which comprises acylindrical tower, a plurality of uniformly spaced gas jets arrangednear the top of the tower, a centrii'ual sprayer supported in theceiling oi.v said tower, means for supplying powdered material to saidsprayer, reflectors associated with said gas jets for reflecting theheat of combustion into the spray plane, and means for exhausting gasand vapors from the lower portion 01' said tower.

CHAMIPLAIN L. RILEY.

